#astrodynamics

• Astronautics — The science and branch of modern technology dealing with the study, design, construction, and operation of spacecraft (rockets, satellites, probes, orbital stations) intended for travel or research outside the Earth's atmosphere. This interdisciplinary discipline gathers advanced knowledge of celestial mechanics (astrodynamics), chemical or nuclear propulsion, onboard electronics, and space medicine to ensure the exploration of the universe.
• Astronavigation — The science, technique, or method of guiding and determining the position, trajectory, and speed of a vehicle (maritime ship, aircraft, or spacecraft) through astronomical observations performed on celestial bodies (Sun, Moon, stars, or reference planets). In the context of modern spaceflight, it represents an essential pillar of astrodynamics, utilizing stable optical sensors (star trackers) for the autonomous orientation of interplanetary probes when ground guidance signals are unavailable.